Pressure vessel



Dec. 4, 1945. V

v VPRESSURE VESSEL Filed D86. 28, 1943 J. w. OVERBEKE 2,390,319

Patented Dec. Y 4, 11945 raEssUaE vEssEL .lohn William Over-beke, New York, N Y., assixnor to Simmonds Aerocessoriles, Inc. of New York, New York, N. Y., a corporation of New York Application December 28, 1943, Serial No. 515,933 4 clams.' (c1. 13s-3o) This invention relates to pressure vessels such as accumulators and surge relievers of the kind used inaircraft, boats and other vinstallations wherein a fluldvis stored or pumped under pressure, and more particularly to those forms of hydraulic system pressure accumulators wherein a noncompressible fluid such as oil and a com" pressible uid such as air are charged under pressure in a shell where they are separated by a flexible membrane.

General objects of the invention4 are to provide pressure vessels of the mentioned types having improved features of construction leading to better performance, easier manufacture; and readier assembly and disassembly.v y

In a copending application of John W. Overbeke, Serial No. 516,167, filed Dec. 30, 1943, there is shown and `generically claimed a pressure ves# sel of the kind herein contemplated, character'- ized by novel means for closing and sealingA the shell mouth and clamping the membrane in position. Particular objects ofthis invention are to provide accumulators having the generally improved features of construction of the mentioned copending application, together with additional improvementsgiving great strength ,coupled with extreme ease in attaching the membrane within the shell and assembling or removing the closure parts, without need for special tools.

Other objects of the invention will in part be obvious and will in part appear hereinafter.

The invention accordingly comprises the features of construction, combination of elements, and arrangement of parts, which will be exemplied in the construction hereinafter set forth,

and the scope of which invention will be indicated in the claims.

For a fuller understanding of the nature and objects of the invention reference should be had to the following detailed description taken in connection with the accompanying drawing, in which:

Fig. l is a vertical sectional view through a pressure accumulator embodying features of the invention Fig. 2 is a fragmentary plan view of the assem- Vbled accumulator; and

line

l' shell.

Within the Shen is a rubber or rubber like membrane, II which in the present instance' is shown as being of bag-like construction occupying the larger part of the shell interior when in inert condition, and having sufficient elasticity to expand up against the shell walls, assuring complete emptyingof the liquid \from the accu mulator when service conditions so demand. The bag-like membrane divides the shell interior into an air compartment I2 and an oil compartment I3.

In the oil compartment there is fitted an oil passing plug I4 which is threaded or otherwise I suitably prepared for connection'with the hydraulic system tubing. Such plug comprises' a perforate plate I5 resting against supporting ribs I6, carried on an lenlarged hollow head Il of the oil plug. Details of this liquid passing plug are more fully described and are claimed in my copending application Serial No. 515,934J filed` Dec. 28, 1943. f

On the other end of the shell are the closure and membrane attaching means the features of which more particularly characterize the ypresent invention. These include a wide mouth or neck I8. capable of allowing insertion of the enlarged head I1 of the oil plug and having a thickenedl wall structure obtainable by accumulating excess metal from the hot spinning process by which the shell is preferably formed. On the inside of` this mouth an annular groove I9 is provided which accommodates a segmented locking ring 20, of steel having high shear resistance, formed of three sections 20a, 20h, and 20c as is best shown in Fig. 3. As illustrated, these ringr sections are so shaped that the entire ring can` be assembled in the groove I9 by inserting 20c last, and it can be disassembled by removing section 20c first. Beneath the locking ring 20 there is a collar 2| which together with the mouth I8 forms a constricted neck portion having a central opening 22. A rubber or other sealingvring 23 is preferably disposed between the collar and shell mouth.

A stopper 24 is slidably fitted in the central collar opening 22 for outward" movement. On the lower end of the stopper there is a stepped flange 25 underlying the lower face of the collar 2| which is grooved as at 26. Within this groove and over the stepped face of the flange 25 there is clamped the edge 21 of the membrane I I, this edge being molded to a proper configuration to fit between the named parts, and being cured so as to retain sufficient plasticity to be deformable when squeezed.

Since the stopper 24 is outwardly slidable through the neck closure, interior pressures within the accumulator force its ange I5 against the membrane edge 2IV and seal the latter with a force that increases in response to interior shell pressures. other suitable sealing ring 28, of conventional form, is disposed between the stopper and the collar. The stopper 24 `has an air passage 29 within which is tted a back check valve 30 Preferably an additional rubber or The collar 2| is held against dropping inwardly away from the locking ring 20 by means ol a holding ring 3| which overlies the outer end of mouth I8 and is pinned tothe collar by means of screws 3|. If wanted, the holding ring 3| may overlie.

and be arrested directly by the locking ring 20. The stopper 24 issimilarly held against inward movement through the collar by means of a nut 33 threaded on its outer end. This nut and the pins 32 are preferably held against unwanted loosening .by a locking wire 34.

In assembly the oil plug |4 is rst inserted through the inside of the shell and welded, brazed, or otherwise suitably attached in place. The membrane which it will be noted can be handled as a unit with the stopper 24, collar 2|, and lock nut 23, is assembled within the shell with lthese named parts which may be dropped sufficiently below the locking ring groove I9 to permit insertion of the several sections of the segmented ring. The closure is then drawn up to the locking ring by means of the screws y32 and holding ring 3|. The accumulator is then ready for insertion in a hydraulic system by means of the oil plug I4, after which the membrane can be charged with air under pressure introduced through the valve 30. The pressure as initially charged may vary within wide limits, but a typical installation may have an initial pressure of 600 p. s. i. when the membrane is fully expanded and there is no,oil under pressure within the shell. This initial compression may be increased to an operating pressure of aroundl500 p. s. i. when the membrane and its contained air is compressed by introduction of oil under pressure in the oil chamber I3. The accumulator construction is rugged enough to handle much higher pressures if Wanted,l those mentioned being cited only as exempliiying current practice.

. It will be seen that the membrane -22 is sealed very tightly in response to the interior shell pressures, and that the various parts are each ruggedly constructed to withstand the forces to which they are subjected.

While the invention has been particularly described with reference to an oleopneumatic accumulator, certain features will be found `useful in systems employing other fluids, and in pressure vessels generally, whether of the accumulator type or not.

Sincecertain changesmay be made in the above construction and different embodiments of the invention could be made without departing from the scope thereof, Ait is intended that all matter contained in the above description or shown in the accompanying drawing shallv be interpreted as illustrative and not in a limiting sense.

"It is also to be understood that the following claims are intended to cover all'of the generic and specic features of the invention herein described, and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween.

Having described my invention, what I claim as new and desire to secure by Letters Patent is:

l. A pressure accumulator comprising, in combination, a shell having an open neck at one end, a centrally open collar snugly fttable within said neck, a stopper outwardly slidable in the central opening of said collar and having a iiange at its lower end underlying said collar, a, flexible baglike membrane having its edges disposed between said flange and collar and adapted to be clamped therebetween when said slidable stopper is subjected to interior bag pressureI said collar, membrane and stopper being capable of preassembly as a unit which can be inserted through said shell neck from outside the shell to divide said shell into compartments, a. locking ring 4iastenable in said shell neck above said collar after said unit has been inserted, and means for passing iiuid in and out of said compartments.

2. A pressure accumulator comprising, in combination, a shellhaving an open'neck at one end, a centrally open collar snugly flttable within said neck, a stopper having a body slidable in land projecting above the central opening of said collar and having a flange at its lower end underlying said collar,` a flexible bag-like membrane having its edges disposed between said flange and collar and adapted to be clamped therebetween when said slidable stopper is' subjected to interior membrane pressure, a holding means fastenable to the upwardly projecting part of said stopper to hold it, said membrane and said collar together as a subassembly capable of being inserted as a unit through said shell neck from outside the shell' whereby said membrane divides said shell into compartments, locking means fastenable in said neck above said collar after said unit has been inserted, and means for passing fluid in and out of said compartments.

3. A pressure accumulator comprising, in cornbination, a shell having an open neck at one end, a centrally open collar snugly ttable within said neck, a stepper having a'body slidable in and projecting above the central opening of said collar and having a flange at its lower end underlying said collar, a iiexible bag-like membrane above said collar and said locking means to hold having its edges disposed between said flange and collar and adapted to be clamped therebetween when said slidable stopper is subjected to pressure from within said membrane, holding means fastenable to the upwardly projecting part of said stopper to hold it, said membrane and said collar v together as a. subassembly capable of being inserted as a unit through said neck from outside the shell whereby said membrane divides said shell into compartments, locking means fastenable in said neck above said collar to hold saidA subassembly partsy against outward release under interior shell pressure, holding means fastenable said subassembly against dropping inwardly when there is no interior shell pressure, and means forpassing fluid'in and out of said compartments.

4. A pressure accumulator comprising, in combination, a shell having an open neck at one end having an internal annular groove, a closure for said neck comprising a subassembly having a collar fittable in said neck, a stopper ttable beneath said collar and a flexible membrane having its edges clamped between said collar and stopper, said subassembly being insertable through said neck from outside the shell as a unit, a locking ring insertable in said annular groove above said collar -to prevent outward release of said subassembly, and means for passing fluid in and out of said accumulator,y on opposite sides of said membrane.

JOHN WILLIAM OVERBEKE. 

